U.S., Japanese and Australian attack aircraft fly off the coast of Guam during a training exercise in February. (Staff Sgt. Aaron Richardson/U.S. Air Force)

Public safety officials in Guam have distributed a two-page pamphlet advising island residents how to prepare and react should North Korea follow through on threats to launch a nuclear strike against the U.S. territory.

The document includes several ominous warnings, the first being: “Do not look at the flash or fireball — It can blind you.”

It also highlights steps for determining what shelters are “safe” — and for removing radioactive material that may accumulate on people's clothes, skin and hair. (Do use shampoo, it says. Don't use conditioner, as it will bind the toxins to your hair.)

Distributed by Guam's Homeland Security Department, the guidance comes as President Trump trades increasingly hostile and alarming statements with the regime in Pyongyang, which has said it's developing plans to attack the Western Pacific atoll.

The government fact sheet would seem a jarring departure from an announcement from Guam Gov. Eddie Baza Calvo, who sought Wednesday to reassure the island's 160,000 citizens, saying in a video address:

“I know we woke up to media reports of North Korea’s talk of revenge on the United States and this so-called newfound technology that allows them to target Guam. I'm working with Homeland Security, the rear admiral and the United States to ensure our safety, and I want to reassure the people of Guam that currently there is no threat to our island or the Marianas.”

The governor of Guam, Eddie Baza Calvo, said on Aug. 9 that there has been "no change in the threat level to Guam," after North Korea and President Trump traded threats. (Eddie Baza Calvo)

Calvo said Wednesday that “there is no change in the threat level resulting from North Korea events” and that “there are several levels of defense, all strategically placed to protect our island and our nation.”

Though officials on the island are clearly mindful of the heated back-and-forth between Washington and Pyongyang, the guidance issued to residents Friday is simply an extension of long-standing public safety practices designed for typhoons and other natural disasters that menace the region.

“Our office hasn't received too many concerned calls,” Jenna Gaminde, a spokeswoman for Guam Homeland Security, told The Washington Post on Friday about the U.S.-North Korean rhetoric. “We've had a few here and there, [but] our lines blow up when there's a natural event. People are calm. We try to assure them there are defense capabilities in place, and people are putting their faith in them.”

Approximately 2,200 miles from North Korea, the island houses about 7,000 U.S. troops, including special operations forces, spread between Andersen Air Force Base and Naval Base Guam. It's a launching point for the strategic bombers that make routine show-of-force flights over the Korean peninsula, and for nuclear submarines home ported there.

Local public safety officials have maintained constant communication between base commanders and the governor's office, Gaminde said.

The fact sheet, first reported Friday by the Pacific Daily News, explains that brick or concrete structures are the safest places to shelter from nuclear fallout, and that those with thick walls and roofs best absorb radioactive particles. Plan to remain inside for at least 24 hours, it says.

Those who can't get indoors or behind some type of protections should simply lie down and cover their heads.

“If the explosion is some distance away,” the fact sheet says, “it could take 30 seconds or more for the blast wave to hit.”

To prevent radioactive material from spreading, people should remove their outer clothing, seal it in a plastic bag and get as far away as possible, the fact sheet says. If possible, shower with soap and water — no conditioner! — but be careful not to scratch the skin. Blow your nose, and wipe out your ears and eyelids, it says.

Officials say the fact sheet was created during a period of similar tension four years ago and dusted off now with hopes that it would encourage residents to plan.

Still, Dee Cruz, a senior watch officer with Guam Homeland Security, concedes that “folks here are concerned because there's a lot of talk about it” — alluding to extensive media coverage of the public statements made by Trump and his counterpart in North Korea, Kim Jong Un.

The island remains on alert, she said, but its government and its people have steeled themselves for the worst.

“Our island has been a target since 2013, and even before that,” Cruz told The Post. “We're ready, and prepared, as much as possible.”